Sectional non-rotative insulating-knob for supporting electric wires



A. M. POINDEXTER.

SECTIONAL NON-ROTATIVE INSULATING KNOB FOR SUPPORTING ELECTRIC WIRES.

APPL CATION FILED MAY I, I917- 1,326,'962 Patented Jan. 6,1920.

ALFRED M. POINDEXTER, OF DENVER, GQLORADO.

SECTIONAL NON-ROTATIVE INSULATING-KNOB FOR SUPPORTING ELECTRIC WIRES.

Application filed May 1, 1917.

To all whom it may concern:

lie it known that I, Acrnnn M. PorNnnX- (ran, a citizen of the United States of Amen .ica, residing at the city and county o'fDen- Yer and State of Colorado, have invented a new and useful Sectional Non-Rotative lnsulating-Knob for Supporting Electric ll ires, of which the following is a specification.

My invention relates to a sectional noni-otative insulating knob for supporting electric wires; and the objects of my invention are:

First, to provide a sectional insulating knob that so constructed and arranged that one member cannot turn independently of the other member or members.

Eiecoi'id, to provide a knob that is adapted to support one or two or more circuit wires, and that may be made in two or more sections. And

l hird, to provide a sectional insulating knob in which the two or more parts of the mob are held vertically or horizontally in axial alineinent, so that one part cannot turn on the other part after the wires have been put in their receiving groove-s that are formed to receive them in the meeting surfaces of the sections.

1 attain these objects by the mechanism illustrated in the accompanying drawings, in which:

Figure l, is a side elevation of the inipro rod knob.

2, is a vertical sectional view of the SillnQ.

Fig. 3, is a bottom view of the nail-holding or head section of the knob.

Fig. 4:, is a plan view of the other section thereof.

F 5, is a plan view of the knob showing a pair of wires extending through the ams.

Figs. 6, T, 8 and 9 are cross sectional views of liiiere'nt styles of nails which can be used with the knob. And

Fig. 10, is a view of a modified form of securing nail.

Similar letters of reference refer to similar parts throughout the several views.

Wire supporting knobs in common use have certain objectionable features which the present invention is designed to overcome. Such knobs are sectional or composed oil two members having registering wire-receiving grooves, but they are pro Specification of Letterslatent.

Patented Jan. 6, 1920.

Serial m. 165,729.

vided with circular axial apertures to receive a securing nail which is circular in cross section, and the sections are usually provided one with a groove or recess, and the other with a corresponding projection or tongue which when fitted in the recess of the other section causes the wire-receiving recesses in the two sections to register and thereby to properly receive the wire. It will readily be seen, however, that the round nail will not prevent rotation or twisting of the parts of the knob and when a Wire is clamped between the two parts and drawn upon, a twisting of the knob is a natural result, and this not only has an injurious effect upon the wire, but prevents the wire from slipping freely through the grooves when being tightened.

The present invention entirely eliminates all of the objectionable features by providing knob sections having square apertures which receive a square. or other fiat sided form of nail, which obviously prevents rotation of the sections of the knob thereon, and which also causes the wire receiving grooves of the two sections to register, thereby elin'iinating the tongue and groove of the common form of knob, all or which will be hereinafter fully set forth.

Referring to the accompanying drawings:

The numeral 1, refers to the head section of the knob, and 2 to the base section thereof, and these sections are made of suitable insulating material, such as glass or por celain, preferably the latter. The sections are provided preferably with square axial holes 3 and 4: respectively, but these holes may be triangular or rectangular or of any other suitable form, in which case a nail having a corresponding cross-section would be employed, cross-sections of various forms of nails being shown in Figs. 6, 7, 8 and 9, any one of which would serve the purpose of preventing rotation of the sections of the knob thereon.

I have, however, illustrated square holes in the knob sections, and a square nail 5, and while the holes may be of a size to permit the nail to slip easily through both of them, it is preferable to have the nail fit tightly in the head section, and loosely enough in the base section to permit the latter to be readily slipped upon the'nail.

A washer 6 of leather or other suitable material is interposed between the head of the nail, and the adjoining end of the head section, to prevent injury or b eakage to the section when the nail is being driven into a pole or other wire support, as will be understood.

Tn the abutting ends of the head and base sections of the knob, and on opposite sides of the axial holes, are formed straight, parallel, V-shaped, wire-receiving grooves 7 and 8, respectively, and which also run parallel with the adjacent side ofthe holes, and this arrangement eliminates the tongue and groove of the common style of knob for centering the sections of the knob to cause the wire grooves to register, this feature being accomplished in the present instance by the square nail and the square hole.

The registering grooves 7 and 8 are each provided with a plurality of transverse knife edge lips 9, which are adapted to become slightly en'ibedded in the wire 10, when the head is driven down upon the said wires, and these lips thus prevent slipping of the wires when once clamped between the head and base. The outer end of the base section is cupped, as shown, which reduces material and permits this end to rest squarely against the object in which the nail is driven. In practice, the base 2 is slipped upon the nail 5, and the nail is then partially driven into the pole or other object, the wire grooves in the knob sections being arranged to stand parallel with the direction of the wires to be strung. The wires are then passed in between the head and base and placed in the grooves 8 in the base; then, after the wire has been suiliciently tightened, the head is driven down until its groove 7 forcibly engages the wire, which is thus clamped between the lips of the grooves 7 and 8, the washer preventing breaking of the parts from the impact of the hammer of the workman.

If desired, the clamping grooves may be omitted in one of the sections.

In Fig. I have illustrated a nail 11, which is split centrally of its width and in that part which lies within the base section of the knob, asshown at 12. This split slightly bulges or widens the nail at this point o that its sides will engage frictionally with the sides of the aperture in the base section.

This arrangement enables the parts to be assembled to remain thus, as the triotional engagement of the nail with the base section will prevent the base section from slipping ofi the nail, thereby greatly facilitating the handling of the knob.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

A wire clamping knob of the character described, comprising a nail which is split centrally for a portion of its length thereby to bulge its sides, head and base clamping sections non-rotatively mounted on said nail, the base section being in frictional engagement with the bulged sides of the nail and being thereby prevented from slipping elf the same.

In testimony whereof I my signature in presence of two witnesses.

ALFRED M. POINDEXTER.

Witnesses G. SARGENT ELLIOTT, ABEL-LA M. Fownn. 

